Amino(iodo)silane precursors for ALD/CVD silicon-containing film applications and methods of using the same

ABSTRACT

Disclosed are amino(iodo)silane precursors, methods of synthesizing the same, and methods of using the same to deposit silicon-containing films using vapor deposition processes. The disclosed amino(iodo)silane precursors include SiH 2 I(N(iPr) 2 ) or SiH 2 I(N(iBu) 2 ).

TECHNICAL FIELD

Disclosed are Si-containing film forming compositions, methods ofsynthesizing the same, and methods of using the same to depositsilicon-containing films using vapor deposition processes formanufacturing semiconductors, photovoltaics, LCD-TFT, flat panel-typedevices, refractory materials, or aeronautics. The disclosedSi-containing film forming compositions comprise an amino(iodo)silaneprecursor selected from SiH₂I(N(iPr)₂), SiH₂I(N(iBu)₂), or combinationsthereof.

BACKGROUND

Si-containing thin films may be used, for example, as dielectricmaterials having electrical properties which may be insulating (SiO₂,SiN, SiCN, SiCOH, MSiO_(x), wherein M is Hf, Zr, Ti, Nb, Ta, or Ge and xis greater than zero), and also used as conducting films, such as metalsilicides or metal silicon nitrides. Due to the strict requirementsimposed by downscaling of electrical device architectures towards thenanoscale, especially below 28 nm node, increasingly fine-tunedmolecular precursors are required which meet the requirements ofvolatility for atomic layer deposition (ALD) and chemical vapordeposition (CVD) processes, lower process temperatures, reactivity withvarious oxidants and low film contamination, in addition to highdeposition rates, conformality and consistency of films produced.

Anderson et al. disclose preparation, properties and vibrational spectraof some dimethylaminohalogenosilanes, including SiH₂I(NMe₂) (J. Chem.Soc. Dalton Trans. 1987, pp. 3029-3034). Anderson was not able todetermine the melting point of the white solid because the sampleexhibited some decomposition when warmed above room temperature. Id. atp. 3030.

Emsley discloses synthesis and analysis of severalaminosilane-iodosilane adducts, which decomposed to form H₂SiINEt₂ orH₂SiI-piperidine.

Organoamino(halo)silanes have also been used as precursors for ALD/CVDof Si-containing films. U.S. Pat. No. 7,125,582 B2 to McSwiney et al.discloses the use of amino(halo)silanes for low-temperature siliconnitride deposition. Tris(dimethylamino)chlorosilane is disclosed inMcSwiney et al.

WO2012/167060 to Xiao et al. discloses, among others,organoaminodisilane precursors having a formula of R⁸N(SiR⁹LH)₂ as aprecursor, wherein L=Cl, Br, or I and R⁸ and R⁹ are each independentlyselected from the group consisting of hydrogen, C₁ to C₁₀ linear orbranched alkyl, a C3 to C10 cyclic alkyl group, a linear or branched C₂to C₁₀ alkenyl group, a linear or branched C₂ to C₁₀ alkynyl group, a C₅to C₁₀ aromatic group, and a C₃ to C₁₀ saturated or unsaturatedheterocyclic group.

Niskanen et al (US2014/0273528, US2014/0273531 and US2014/0273477)discloses, among others, mixed halo Si precursors having formulaH_(2n+2-y-z)Si_(n)X_(y)A_(z)R_(w) where X is I or Br, n=1-10, y=from 1up to 2n+2-z-w, z=from 0 up to 2n+2-y-w, w=from 0 up to 2n+2-y-z, A ishalogen other than X, and R is an organic ligand and can beindependently selected from the group consisting of alkoxides,alkylsilyls, alkyl, substituted alkyl, alkylamines and unsaturatedhydrocarbon. Exemplary precursors include SiI₂H(NH₂), SiI₂H(NHMe),SiI₂H(NHEt), SiI₂H(NMe₂), SiI₂H(NMeEt), SiI₂H(NEt₂), SiI₂(NH₂)₂,SiI₂(NHMe)₂, SiI₂(NHEt)₂, SiI₂(NMe₂)₂, SiI₂(NMeEt)₂, and SiI₂(NEt₂)₂.

US2012/0021127 to Sato et al. discloses a material for CVD containing anorganic silicon-containing compound represented by formula:HSiCl(NR¹R²)(NR³R⁴), wherein R¹ and R³ each represent C₁-C₃ alkyl orhydrogen; and R² and R⁴ each represent C₁-C₃ alkyl.

US2012/0277457 to Lehmann et al discloses a haloaminosilane compoundhaving the following formula: X_(4-n)H_(n-1)SiN(CH(CH₃)₂)₂ wherein n is1, 2 and 3; and X is a halogen selected from Cl, Br, or a mixture of Cland Br, including Br₃SiNiPr₂

US2013/0078392 to Xiao et al. discloses a composition for the depositionof a dielectric film comprising: X_(m)R¹ _(n)H_(p)Si(NR²R³)_(4-m-n-p),wherein X is a halide selected from the group consisting of Cl, Br, I,including H₂ClSi(NR₂) or HCl₂Si(NR₂), with R=Me, Et, iPr, sBu, iBu,cyclohexyl, pheny, perhydroquinoline, 2,6-dimethylpiperidino, and more.

Despite the wide range of choices available for the deposition of Sicontaining films, additional precursors are continuously sought toprovide device engineers the ability to tune manufacturing processrequirements and achieve films with desirable electrical and physicalproperties.

SUMMARY

Disclosed are Si-containing film forming compositions comprising anamino(iodo)silane precursor having the formula:SiH_(x)I_(y)(NR¹R²)_(z)  (I)wherein x+y+z=4; x=0, 1 or 2; y=1, 2 or 3; z=1, 2, or 3; R¹ and R²selected independently from C₃-C₆ alkyl, aryl, or hetero group; and R¹and R² may be joined to form a nitrogen-containing heterocycle.

The disclosed Si-containing film forming compositions may have one ormore of the following aspects:

-   -   x=2, y=1, and z=1;    -   the organoamino(iodo)silane precursor having the formula:

-   -   the organoamino(iodo)silane precursor being:

-   -   the organoamino(iodo)silane precursor being:

-   -   the organoamino(iodo)silane precursor being:

-   -   the organoamino(iodo)silane precursor being:

-   -   the amino(iodo)silane precursor being:

-   -   R¹ and R² being joined to form a cyclic nitrogen-containing        heterocycle;    -   the amino(iodo)silane precursor being:

-   -   the amino(iodo)silane precursor being:

-   -   the amino(iodo)silane precursor being:

-   -   the amino(iodo)silane precursor being:

-   -   the amino(iodo)silane precursor being:

-   -   x=1, y=2, and z=1;    -   the amino(iodo)silane precursor having the formula:

-   -   the amino(iodo)silane precursor being:

-   -   the amino(iodo)silane precursor being:

-   -   the amino(iodo)silane precursor being:

-   -   the amino(iodo)silane precursor being:

-   -   R¹ and R² being joined to form a cyclic nitrogen-containing        heterocycle;    -   the amino(iodo)silane precursor being:

-   -   the amino(iodo)silane precursor being:

-   -   the amino(iodo)silane precursor being:

-   -   the amino(iodo)silane precursor being:

-   -   the amino(iodo)silane precursor being:

-   -   x=1, y=1, and z=2;    -   the amino(iodo)silane precursor having the formula:

-   -   the amino(iodo)silane precursor being:

-   -   the amino(iodo)silane precursor being:

-   -   the amino(iodo)silane precursor being:

-   -   the amino(iodo)silane precursor being:

-   -   R¹ and R² being joined to form a cyclic nitrogen-containing        heterocycle;    -   the amino(iodo)silane precursor being:

-   -   the amino(iodo)silane precursor being:

-   -   the amino(iodo)silane precursor being:

-   -   the amino(iodo)silane precursor being:

-   -   the amino(iodo)silane precursor being:

-   -   the amino(iodo)silane precursor being:

-   -   x=0, y=3, and z=1;    -   the amino(iodo)silane precursor having the formula:

-   -   the amino(iodo)silane precursor being:

-   -   the amino(iodo)silane precursor being:

-   -   the amino(iodo)silane precursor being:

-   -   R¹ and R² being joined to form a cyclic nitrogen-containing        heterocycle;    -   the amino(iodo)silane precursor being:

-   -   the amino(iodo)silane precursor being:

-   -   the amino(iodo)silane precursor being:

-   -   the amino(iodo)silane precursor being:

-   -   the amino(iodo)silane precursor being:

-   -   the amino(iodo)silane precursor being:

-   -   x=0, y=2, and z=2;    -   the amino(iodo)silane precursor having the formula:

-   -   the amino(iodo)silane precursor being:

-   -   the amino(iodo)silane precursor being:

-   -   the amino(iodo)silane precursor being:

-   -   the amino(iodo)silane precursor being:

-   -   R¹ and R² being joined to form a cyclic nitrogen-containing        heterocycle;    -   the amino(iodo)silane precursor being:

-   -   the amino(iodo)silane precursor being:

-   -   the amino(iodo)silane precursor being:

-   -   the amino(iodo)silane precursor being:

-   -   the amino(iodo)silane precursor being:

-   -   the amino(iodo)silane precursor being:

-   -   x=0, y=1, and z=3;    -   the amino(iodo)silane precursor having the formula:

-   -   the amino(iodo)silane precursor being:

-   -   the amino(iodo)silane precursor being:

-   -   R¹ and R² being joined to form a cyclic nitrogen-containing        heterocycle;    -   the amino(iodo)silane precursor being:

-   -   the amino(iodo)silane precursor being:

-   -   the amino(iodo)silane precursor being:

-   -   the amino(iodo)silane precursor being:

-   -   the amino(iodo)silane precursor being:

-   -   the Si-containing film forming composition comprising between        approximately 99% w/w and approximately 100% w/w of the        amino(iodo)silane precursor;    -   the Si-containing film forming composition comprising between        approximately 99% w/w and approximately 100% w/w of the        amino(iodo)silane precursor after 4 weeks at 50° C.;    -   the Si-containing film forming composition comprising between        approximately 99% w/w and approximately 100% w/w of the        amino(iodo)silane precursor after 12 weeks at room temperature        (approximately 23° C.);    -   the Si-containing film forming composition comprising between        approximately 95% w/w and approximately 100% w/w of the        amino(iodo)silane precursor;    -   the Si-containing film forming composition comprising between        approximately 5% w/w and approximately 50% w/w of the        amino(iodo)silane precursor;    -   the Si-containing film forming composition comprising no water;    -   the Si-containing film forming composition comprising between        approximately 0% w/w and approximately 5% w/w impurities;    -   the Si-containing film forming composition comprising between        approximately 0.0% w/w and approximately 2.0% w/w impurities;    -   the Si-containing film forming composition comprising between        approximately 0.0% w/w and approximately 1.0% w/w impurities;    -   the impurities including ammonium salts; alkylamines;        dialkylamines; alkylimines; iodosilanes; aminosilanes; lithium,        sodium, or potassium iodide; iodine; THF; ether; pentane;        cyclohexane; heptanes; benzene; toluene; halogenated metal        amino(iodo)silane precursors;    -   the Si-containing film forming composition comprising between        approximately 0 ppbw and approximately 1 ppmw metal impurities;    -   the Si-containing film forming composition comprising between        approximately 0 ppbw and approximately 500 ppbw metal        impurities;    -   the Si-containing film forming composition comprising between        approximately 0 ppbw and approximately 100 ppbw Al;    -   the Si-containing film forming composition comprising between        approximately 0 ppbw and approximately 100 ppbw As;    -   the Si-containing film forming composition comprising between        approximately 0 ppbw and approximately 100 ppbw Ba;    -   the Si-containing film forming composition comprising between        approximately 0 ppbw and approximately 100 ppbw Be;    -   the Si-containing film forming composition comprising between        approximately 0 ppbw and approximately 100 ppbw Bi;    -   the Si-containing film forming composition comprising between        approximately 0 ppbw and approximately 100 ppbw Cd;    -   the Si-containing film forming composition comprising between        approximately 0 ppbw and approximately 100 ppbw Ca;    -   the Si-containing film forming composition comprising between        approximately 0 ppbw and approximately 100 ppbw Cr;    -   the Si-containing film forming composition comprising between        approximately 0 ppbw and approximately 100 ppbw Co;    -   the Si-containing film forming composition comprising between        approximately 0 ppbw and approximately 100 ppbw Cu;    -   the Si-containing film forming composition comprising between        approximately 0 ppbw and approximately 100 ppbw Ga;    -   the Si-containing film forming composition comprising between        approximately 0 ppbw and approximately 100 ppbw Ge;    -   the Si-containing film forming composition comprising between        approximately 0 ppbw and approximately 100 ppbw Hf;    -   the Si-containing film forming composition comprising between        approximately 0 ppbw and approximately 100 ppbw Zr;    -   the Si-containing film forming composition comprising between        approximately 0 ppbw and approximately 100 ppbw In;    -   the Si-containing film forming composition comprising between        approximately 0 ppbw and approximately 100 ppbw Fe;    -   the Si-containing film forming composition comprising between        approximately 0 ppbw and approximately 100 ppbw Pb;    -   the Si-containing film forming composition comprising between        approximately 0 ppbw and approximately 100 ppbw Li;    -   the Si-containing film forming composition comprising between        approximately 0 ppbw and approximately 100 ppbw Mg;    -   the Si-containing film forming composition comprising between        approximately 0 ppbw and approximately 100 ppbw Mn;    -   the Si-containing film forming composition comprising between        approximately 0 ppbw and approximately 100 ppbw W;    -   the Si-containing film forming composition comprising between        approximately 0 ppbw and approximately 100 ppbw Ni;    -   the Si-containing film forming composition comprising between        approximately 0 ppbw and approximately 100 ppbw K;    -   the Si-containing film forming composition comprising between        approximately 0 ppbw and approximately 100 ppbw Na;    -   the Si-containing film forming composition comprising between        approximately 0 ppbw and approximately 100 ppbw Sr;    -   the Si-containing film forming composition comprising between        approximately 0 ppbw and approximately 100 ppbw Th;    -   the Si-containing film forming composition comprising between        approximately 0 ppbw and approximately 100 ppbw Sn;    -   the Si-containing film forming composition comprising between        approximately 0 ppbw and approximately 100 ppbw Ti;    -   the Si-containing film forming composition comprising between        approximately 0 ppbw and approximately 100 ppbw U;    -   the Si-containing film forming composition comprising between        approximately 0 ppbw and approximately 100 ppbw V;    -   the Si-containing film forming composition comprising between        approximately 0 ppbw and approximately 100 ppbw Zn;    -   the Si-containing film forming composition comprising between        approximately 0 ppmw and approximately 100 ppmw Cl;    -   the Si-containing film forming composition comprising between        approximately 0 ppmw and approximately 100 ppmw Br.

Also disclosed are methods of depositing a Si-containing layer on asubstrate. The vapor of any of the Si-containing film formingcompositions disclosed above is introduced into a reactor having asubstrate disposed therein. At least part of the amino(iodo)silaneprecursor is deposited onto the substrate to form a Si-containing layerusing a vapor deposition method. The disclosed methods may have one ormore of the following aspects:

-   -   The disclosed Si-containing film forming compositions comprising        an amino(iodo)silane precursor selected from SiH₂I(N(iPr)₂),        SiH₂I(N(iBu)₂), or combinations thereof;    -   The disclosed amino(iodo)silane precursor being SiH₂I(N(iPr)₂);    -   The disclosed amino(iodo)silane precursor being SiH₂I(N(iBu)₂);    -   introducing into the reactor a vapor comprising a second        precursor;    -   an element of the second precursor being selected from the group        consisting of group 2, group 13, group 14, transition metal,        lanthanides, and combinations thereof;    -   the element of the second precursor being selected from Mg, Ca,        Sr, Ba, Zr, Hf, Ti, Nb, Ta, Al, Si, Ge, Y, or lanthanides;    -   introducing a reactant into the reactor;    -   the reactant being selected from the group consisting of O₂, O₃,        H₂O, H₂O₂, NO, NO₂, a carboxylic acid, radicals thereof, and        combinations thereof;    -   the reactant being plasma treated oxygen;    -   the reactant being ozone;    -   the reactant being selected from the group consisting of H₂,        NH₃, (SiH₃)₃N, hydridosilanes (such as SiH₄, Si₂H₆, Si₃H₈,        Si₄H₁₀, Si₅H₁₀, Si₆H₁₂), chlorosilanes and chloropolysilanes        (such as SiHCl₃, SiH₂Cl₂, SiH₃Cl, Si₂Cl₆, Si₂HCl₅, Si₃Cl₈),        alkysilanes (such as Me₂SiH₂, Et₂SiH₂, MeSiH₃, EtSiH₃),        hydrazines (such as N₂H₄, MeHNNH₂, MeHNNHMe), organic amines        (such as NMeH₂, NEtH₂, NMe₂H, NEt₂H, NMe₃, NEt₃, (SiMe₃)₂NH),        pyrazoline, pyridine, B-containing molecules (such as B₂H₆,        9-borabicylo[3,3,1]none, trimethylboron, triethylboron,        borazine), alkyl metals (such as trimethylaluminum,        triethylaluminum, dimethylzinc, diethylzinc), radical species        thereof, and mixtures thereof;    -   the reactant being selected from the group consisting of H₂,        NH₃, SiH₄, Si₂H₆, Si₃H₈, SiH₂Me₂, SiH₂Et₂, N(SiH₃)₃, hydrogen        radicals thereof, and mixtures thereof;    -   the reactant being selected from the group consisting of NH₃,        N₂H₄, N(SiH₃)₃, N(CH₃)H₂, N(C₂H₅)H₂, N(CH₃)₂H, N(C₂H₅)₂H,        N(CH₃)₃, N(C₂H₅)₃, (SiMe₃)₂NH, (CH₃)HNNH₂, (CH₃)₂NNH₂,        nitrogen-containing radical species thereof, and mixtures        thereof;    -   the reactant being HCDS or PCDS;    -   the reactant being plasma treated N₂;    -   the vapor deposition method being a CVD process;    -   the vapor deposition method being an ALD process;    -   the vapor deposition method being a PEALD process; the vapor        deposition method being a spatial ALD process;    -   the Si-containing layer being a silicon oxide layer;    -   the Si-containing layer being Si;    -   the Si-containing layer being SiO₂;    -   the Si-containing layer being SiN;    -   removing the SiN layer;    -   the Si-containing layer being SiON;    -   the Si-containing layer being SiCN; and    -   the Si-containing layer being SiCOH.

Also disclosed is a Si-containing film forming composition deliverydevice comprising a canister having an inlet conduit and an outletconduit and containing any of the Si-containing film formingcompositions disclosed above. The disclosed device may include one ormore of the following aspects:

-   -   the Si-containing film forming composition having a total        concentration of metal contaminants of less than 10 ppmw;    -   an end of the inlet conduit end located above a surface of the        Si-containing film forming composition and an end of the outlet        conduit located below the surface of the Si-containing film        forming composition;    -   an end of the inlet conduit end located below a surface of the        Si-containing film forming composition and an end of the outlet        conduit located above the surface of the Si-containing film        forming composition;    -   further comprising a diaphragm valve on the inlet and the        outlet;    -   further comprising one or more barrier layers on an interior        surface of the canister;    -   further comprising one to four barrier layers on an interior        surface of the canister;    -   further comprising one or two barrier layers on an interior        surface of the canister;    -   each barrier layer comprising a silicon oxide layer, a silicon        nitride layer, silicon oxynitride layer, a silicon carbonitride,        silicon oxycarbonitride layer, or combinations thereof;    -   wherein each barrier layer is 5 to 1000 nm in thickness;    -   wherein each barrier layer is 50 to 500 nm in thickness;    -   the Si-containing film forming composition comprising        SiH₂I(N(iPr)₂); and    -   the Si-containing film forming composition comprising        SiH₂I(N(iBu)₂).

NOTATION AND NOMENCLATURE

The following detailed description and claims utilize a number ofabbreviations, symbols, and terms, which are generally well known in theart. While definitions are typically provided with the first instance ofeach acronym, for convenience, Table 1 provides a list of theabbreviations, symbols, and terms used along with their respectivedefinitions.

TABLE 1 a or an One or more than one Approximately ±10% of the valuestated or about LCD-TFT liquid-crystal display TFT thin-film transistorMIM Metal-insulator-metal DRAM dynamic random-access memory FeRamFerroelectric random-access memory CVD chemical vapor deposition LPCVDlow pressure chemical vapor deposition PCVD pulsed chemical vapordeposition SACVD sub-atmospheric chemical vapor deposition PECVD plasmaenhanced chemical vapor deposition APCVD atmospheric pressure chemicalvapor deposition HWCVD hot-wire chemical vapor deposition Flowableflowable plasma enhanced chemical vapor deposition PECVD MOCVD metalorganic chemical vapor deposition ALD atomic layer deposition spatialALD spatial atomic layer deposition HWALD hot-wire atomic layerdeposition PEALD plasma enhanced atomic layer deposition DSSD dualsilicone source deposition sccm standard cubic centimeters per minute MPmelting point TGA thermogravimetric analysis SDTA simultaneousdifferential thermal analysis GCMS gas chromatography-mass spectrometrySRO strontium ruthenium oxide HCDS Hexachlorodisilane PCDSPentachlorodisilane LAH lithium aluminum hydride TriDMAS orTris(dimethylamino)silane or SiH(NMe₂)₃ TDMAS BDMASBis(dimethylamino)silane or SiH₂(NMe₂)₂ BDEAS Bis(diethylamino)silane orSiH₂(NEt₂)₂ TDEAS Tris(diethylamino)silane or SiH(NEt₂)₃ TEMASTris(ethylmethylamino)silane or SiH(NEtMe)₃ TMA trimethyl aluminum orAlMe₃ TBTDET (tert-butylimido)tris(diethylamido) tantalum orTa(═NtBu)(NEt₂)₃ TAT-DMAE tantalum tetraethoxide dimethylaminoethoxideor Ta(OEt)₄(OCH₂NMe₂) PET polyethylene terephthalate TBTDEN(tert-butylimido)bis(dimethylamino)niobium or Nb(═NtBu)(NMe₂)₂ PENpolyethylene naphthalate Ln(tmhd)₃ lanthanide(2,2,6,6-tetramethyl-3,5-heptanedione)₃ alkyl group saturated functionalgroups containing exclusively carbon and hydrogen atoms, includinglinear, branched, or cyclic alkyl groups aryl aromatic ring compoundswhere one hydrogen atom has been removed from the ring Hetero afunctional group containing C and a second non-H element, such as S or Oheterocycle cyclic compounds that has atoms of at least two differentelements as members of its ring Me Methyl Et Ethyl Pr Propyl, includingiPr and nPr iPr iso-Propyl nPr n-Propyl Bu Butyl, including iBu, sBu,and tBu iBu iso-Butyl sBu Sec-Butyl tBu Tert-Butyl

The standard abbreviations of the elements from the periodic table ofelements are used herein. It should be understood that elements may bereferred to by these abbreviations (e.g., Si refers to silicon, N refersto nitrogen, O refers to oxygen, C refers to carbon, etc.).

Any and all ranges recited herein are inclusive of their endpoints(i.e., x=1 to 4 includes x=1, x=4, and x=any number in between).

As used herein, the term “independently” when used in the context ofdescribing R groups should be understood to denote that the subject Rgroup is not only independently selected relative to other R groupsbearing the same or different subscripts or superscripts, but is alsoindependently selected relative to any additional species of that same Rgroup. For example in the formula MR¹ _(X) (NR²R³)_((4-x)), where x is 2or 3, the two or three R¹ groups may, but need not be identical to eachother or to R² or to R³. Further, it should be understood that unlessspecifically stated otherwise, values of R groups are independent ofeach other when used in different formulas.

Please note that the films or layers deposited, such as silicon oxide orsilicon nitride, may be listed throughout the specification and claimswithout reference to their proper stoichiometry (i.e., SiO₂, SiO₃,Si₃N₄). The layers may include pure (Si) layers, carbide (Si_(o)C_(p))layers, nitride (Si_(k)N_(l)) layers, oxide (Si_(n)O_(m)) layers, ormixtures thereof, wherein k, l, m, n, o, and p inclusively range from 1to 6. For instance, silicon oxide is Si_(n)O_(m), wherein n ranges from0.5 to 1.5 and m ranges from 1.5 to 3.5. More preferably, the siliconoxide layer is SiO₂ or SiO₃. The silicon oxide layer may be a siliconoxide based dielectric material, such as organic based or silicon oxidebased low-k dielectric materials such as the Black Diamond II or Illmaterial by Applied Materials, Inc. Alternatively, any referencedsilicon-containing layer may be pure silicon. Any silicon-containinglayers may also include dopants, such as B, C, P, As and/or Ge.

BRIEF DESCRIPTION OF THE DRAWINGS

For a further understanding of the nature and objects of the presentinvention, reference should be made to the following detaileddescription, taken in conjunction with the accompanying drawings, inwhich like elements are given the same or analogous reference numbersand wherein:

FIG. 1 is a side view of one embodiment of the Si-containing filmforming composition delivery device 1;

FIG. 2 is a side view of a second embodiment of the Si-containing filmforming composition delivery device 1;

FIG. 3 is a Thermogravimetric Analysis (TGA) graph demonstrating thepercentage of weight loss with increasing temperature of SiHI(NMe₂)₂;

FIG. 4 is a TGA graph demonstrating the percentage of weight loss withincreasing temperature of SiH₂I(NEt₂);

FIG. 5 is a TGA graph demonstrating the percentage of weight loss withincreasing temperature of SiH₂I(N^(i)Pr₂);

FIG. 6 is a TGA graph demonstrating the percentage of weight loss withincreasing temperature of SiH₂I(N^(i)Bu₂);

FIG. 7 is a graph demonstrating the purity over time for the precursorsincluded in Examples 1-3 stored at 24° C.;

FIG. 8 is a graph demonstrating the purity over time for the precursorsincluded in Examples 1-3 stored at 40° C. (SiH₂I(NEt₂)) and 50° C.(SiH₂I(N^(i)Pr₂) and SiH₂I(N^(i)Bu₂));

FIG. 9 is a graph showing the deposition rate and refractive index ofsilicon nitride films from SiH₂I(N^(i)Bu₂) and plasma N₂ as a functionof the precursor introduction pulse time in seconds;

FIG. 10 is a graph showing the deposition rate and refractive index ofsilicon nitride films from SiH₂I(N^(i)Pr₂) and plasma N₂ as a functionof the precursor introduction pulse time in seconds; and

FIG. 11 is a graph showing the deposition rate and refractive index ofsilicon nitride films from SiH₂Cl(N^(i)Pr₂) and plasma N₂ as a functionof the precursor introduction pulse time in seconds.

DESCRIPTION OF PREFERRED EMBODIMENTS

Disclosed are Si-containing film forming compositions comprisingamino(iodo)silane precursors having the following formula:SiH_(x)I_(y)(NR¹R²)_(z)  (I)wherein x+y+z=4; x=0, 1 or 2; y=1, 2 or 3; z=1, 2, or 3; R¹ and R²selected independently from C₃-C₆ alkyl, aryl, or hetero group; and R¹and R² may be joined to form a cyclic nitrogen-containing heterocycle.

The disclosed amino(iodo)silane precursors contains one, two, or threeiodine atoms directly bonded to the Si atom. These Si—I bonds may helpto provide a larger growth rate per cycle when compared to the analogousSi—Cl containing precursors because the Si—I bond energy is lower thanthe Si—Cl bond energy. Additionally, I has a larger atomic radius thanCl, which may help to prevent I contamination in the resulting film.Notwithstanding any potential I contamination, the improved depositionrate provides the ability to rapidly deposit sacrificial layers andincrease process throughput.

The disclosed amino(iodo)silane precursors may contain one or twohydrogen atoms directly bonded to the Si atom. These Si—H bonds may helpincrease the volatility of the precursor, which is important for vapordeposition processes.

The disclosed amino(iodo)silane precursors contain one, two, or threeamino groups directly bonded to the Si atom. These Si—N bonds may helpincrease thermal stability of the precursor, which is also important forvapor deposition processes. The amino group may also help incorporate Nand C atoms into the resulting film, which may make the resulting layermore resistant to any subsequent etching processes.

One of ordinary skill in the art will recognize that the volatilityprovided by the Si—H bonds competes directly with the thermal stabilityprovided by the amino groups. Applicants believe that SiH₂I(N(iPr)₂)and/or SiH₂I(N(iBu)₂) successfully balance those competingcharacteristics.

When R¹ and R² form a cyclic nitrogen-containing heterocycle, Applicantsbelieve that the resulting heterocycle forms a leaving group that may beeasily detached from the organo(iodo)silane precursor, resulting in lesscarbon contamination of the resulting film as compared to the acyclicdialkyl amino groups.

Preferably, the disclosed Si-containing film forming compositions havesuitable properties for vapor depositions methods, such as vaporpressure ranging from approximately 0.1 Torr at 23° C. to approximately1,000 Torr at 23° C., a melting point below 20° C. (preferably being inliquid form at room temperature) and more preferably below −20° C. toprevent freeze/thaw issues, and exhibiting 0% v/v to 1% v/vdecomposition per week at the desired process temperature. A bulkier Rgroup on the amine, such as iPr or tBu, may help stabilize the disclosedSi-containing film forming compositions, helping to preventdecomposition.

The disclosed Si-containing film forming compositions may be suitablefor the deposition of Si-containing films, such as, Si, SiO₂, SiON,SiCOH, SiCN, SiN, MSiOx (here M may be an element such as Hf, Zr, Ti, V,Nb, Ta, or Ge, and x may be 0-4 depending upon the oxidation state of M)films by various ALD or CVD processes, such as, ALD, PEALD, PVD, CVD,PECVD, flowable ALD/CVD, DSSD, selective ALD, and may have the followingadvantages:

-   -   liquid at room temperature or having a melting point lower than        50° C.;    -   thermally stable to enable proper distribution (gas phase or        direct liquid injection) without particles generation;    -   suitable reactivity with the substrate to permit a wide        self-limited ALD window, allowing deposition of a variety of        Si-containing films, such as SiGe or SiSn, including ternary or        quaternary materials, by using one or a combination of reactants        (selected from the group comprising of H₂, NH₃, O₂, H₂O, O₃,        SiH₄, Si₂H₆, Si₃H₈, SiH(NMe₂)₃ (TriDMAS or TDMAS), SiH₂(NMe₂)₂        (BDMAS), SiH₂(N(Et)₂)₂ (BDEAS), SiH(N(Et)₂)₃(TDEAS), SiH(NEtMe)₃        (TEMAS), (SiH₃)₃N, (SiH₃)₂O, (GeH₃)₂, Bu₄Ge, GeMe₄, GeEt₄,        Ge(allyl), (Ge(NMe₂)₄, Ge(N(SiMe₃)₂)₄, GeCl₂-dioxane, GeBr₂,        GeCl₄, Ge(OMe)₄, Ge(OEt)₄, Sn(O^(t)Bu)₄, SnI₄, SnMe₄, Sn(AcAc)₂,        Sn(NMe₂)₄, Sn(NEt₂)₄, Sn(N(SiMe₃)₂)₂, an aluminum-containing        precursor such as trimethyl aluminum (TMA),        (tert-butylimido)tris(diethylamido) tantalum (TBTDET), tantalum        tetraethoxide dimethylaminoethoxide (TAT-DMAE), polyethylene        terephthalate (PET), (tert-butylimido)bis(dimethylamino)niobium        (TBTDEN), polyethylene naphthalate (PEN), lanthanide-containing        precursors such as Ln(tmhd)₃ (lanthanide        (2,2,6,6-tetramethyl-3,5-heptanedione)₃)).

When x=2, y=1, z=1 in formula (I), exemplary amino(iodo)silaneprecursors include SiH₂I(NR¹R²) and each precursor molecule contains onenitrogen donor, one iodide and two hydride functional groups, have thestructural formula:

wherein R¹ and R² selected independently from C₃-C₆ alkyl, aryl, orhetero group and R¹ and R² may be joined to form a cyclicnitrogen-containing heterocycle.

Exemplary amino(iodo)silanes having the formula SiH₂I(NR¹R²) include:

As demonstrated in the examples that follow, SiH₂I(NiBu₂) is more stablethan its SiH₂I(NMe₂), SiH₂I(NEt₂) and SiH₂I(NiPr₂) analogs, exhibitinglittle decomposition after stability testing at 50° C. for 4 weeks.

The above listed SiH₂I(NR¹R²) precursors may be synthesized by firstloading the reaction flask with a hydrocarbon solution of diiodosilane,chilling the solution to −78° C. and addition of a hydrocarbon solutioncontaining two equivalents of the appropriate amine. The resultingsuspension may be filtered over a glass fritted filter and the solventremoved to afford the crude product. Alternatively, the above listedSiH₂I(NR¹R²) precursors may be synthesized by first reacting a chilledhydrocarbon solution of the appropriate amine with one equivalent of ahydrocarbon solution of an alkyl lithium reagent. The resulting lithiumamide suspension may then be added to a chilled hydrocarbon solutioncontaining one equivalent of diiodosilane followed by filtration on aglass frit and removal of solvent to afford the product. An additionalroute to the above listed SiH₂I(NR¹R²) precursors is to add a neatpreparation of SiH₂(NR¹R²)₂ slowly to a chilled flask containing anequimolar amount of diiodosilane. The resulting suspension may be warmedto room temperature while stirring to afford the product.

When x=1, y=2, z=1 in formula (I), exemplary amino(iodo)silaneprecursors include SiHI₂(NR¹R²) and each precursor molecule contains onenitrogen donor, two iodide and one hydride functional group, have thestructural formula:

wherein R¹ and R² selected independently from C₃-C₆ alkyl, aryl, orhetero group and R¹ and R² may be joined to form a cyclicnitrogen-containing heterocycle.

Exemplary amino(iodo)silanes having the formula SiHI₂(NR¹R²) include:

The above listed SiHI₂(NR¹R²) precursors may be synthesized by firstloading the reaction flask with a hydrocarbon solution of triiodosilane,chilling the solution to −78° C. and addition of a hydrocarbon solutioncontaining two equivalents of the appropriate amine. The resultingsuspension may be filtered over a glass fritted filter and the solventremoved to afford the crude product. Alternatively, the above listedSiHI₂(NR¹R²) precursors may be synthesized by first reacting a chilledhydrocarbon solution of the appropriate amine with one equivalent of ahydrocarbon solution of an alkyl lithium reagent. The resulting lithiumamide suspension may then be added to a chilled hydrocarbon solutioncontaining one equivalent of triiodosilane followed by filtration on aglass frit and removal of solvent to afford the product. An additionalroute to the above listed SiHI₂(NR¹R²) precursors is to add a neatpreparation of SiH(NR¹R²)₃ slowly to a chilled flask containing twoequivalents of triiodosilane. The resulting suspension may be warmed toroom temperature while stirring to afford the product.

When x=1, y=1, z=2 in formula (I), exemplary amino(iodo)silaneprecursors include SiHI(NR¹R²)₂ and each precursor molecule contains twonitrogen donors, one iodide and one hydride functional group, have thestructural formula:

wherein R¹ and R² selected independently from C₃-C₆ alkyl, aryl, orhetero group and R¹ and R² may be joined to form a cyclicnitrogen-containing heterocycle.

Exemplary amino(iodo)silanes having the formula SiHI(NR¹R²)₂ include:

The above listed SiHI(NR¹R²)₂ precursors may be synthesized by firstloading the reaction flask with a hydrocarbon solution of triiodosilane,chilling the solution to −78° C. and addition of a hydrocarbon solutioncontaining four equivalents of the appropriate amine. The resultingsuspension may be filtered over a glass fritted filter and the solventremoved to afford the crude product. Alternatively, the above listedSiHI(NR¹R²)₂ precursors may be synthesized by first reacting a chilledhydrocarbon solution of two equivalents of the appropriate amine withtwo equivalents of a hydrocarbon solution of an alkyl lithium reagent.The resulting lithium amide suspension may then be added to a chilledhydrocarbon solution containing one equivalent of triiodosilane followedby filtration on a glass frit and removal of solvent to afford theproduct. An additional route to the above listed SiHI(NR¹R²)₂ precursorsis to add a neat preparation of SiH(NR¹R²)₃ slowly to a chilled flaskcontaining 0.5 equivalents of triiodosilane. The resulting suspensionmay be warmed to room temperature while stirring to afford the product.

When x=0, y=3, z=1 in formula (I), exemplary amino(iodo)silaneprecursors include SiI₃(NR¹R²) and each precursor molecule contains onenitrogen donor, three iodide and no hydride functional group, have thestructural formula:

wherein R¹ and R² selected independently from C₃-C₆ alkyl, aryl, orhetero group and R¹ and R² may be joined to form a cyclicnitrogen-containing heterocycle.

Exemplary amino(iodo)silanes having the formula SiI₃(NR¹R²) include:

The above listed SiI₃(NR¹R²) precursors may be synthesized by firstloading the reaction flask with a hydrocarbon suspension of silicontetraiodide, chilling the solution to −78° C. and addition of ahydrocarbon solution containing two equivalents of the appropriateamine. The resulting suspension may be filtered over a glass frittedfilter and the solvent removed to afford the crude product.Alternatively, the above listed SiI₃(NR¹R²) precursors may besynthesized by first reacting a chilled hydrocarbon solution theappropriate amine with one equivalent of a hydrocarbon solution of analkyl lithium reagent. The resulting lithium amide suspension may thenbe added to a chilled hydrocarbon suspension containing one equivalentof silicon tetraiodide followed by filtration on a glass frit andremoval of solvent to afford the product.

When x=0, y=2, z=2 in formula (I), exemplary amino(iodo)silaneprecursors include SiI₂(NR¹R²)₂ and each precursor molecule contains twonitrogen donors, two iodide and no hydride functional group, have thestructural formula:

wherein R¹ and R² selected independently from C₃-C₆ alkyl, aryl, orhetero group and R¹ and R² may be joined to form a cyclicnitrogen-containing heterocycle.

Exemplary amino(iodo)silanes having the formula SiI₂(NR¹R²)₂ include:

The above listed SiI₂(NR¹R²)₂ precursors may be synthesized by firstloading the reaction flask with a hydrocarbon suspension of silicontetraiodide, chilling the solution to −78° C. and addition of ahydrocarbon solution containing four equivalents of the appropriateamine. The resulting suspension may be filtered over a glass frittedfilter and the solvent removed to afford the crude product.Alternatively, the above listed SiI₂(NR¹R²)₂ precursors may besynthesized by first reacting a chilled hydrocarbon solution containingtwo equivalents of the appropriate amine with two equivalents of ahydrocarbon solution of an alkyl lithium reagent. The resulting lithiumamide suspension may then be added to a chilled hydrocarbon suspensioncontaining one equivalent of silicon tetraiodide followed by filtrationon a glass frit and removal of solvent to afford the product.

When x=0, y=1, z=3 in formula (I), exemplary amino(iodo)silaneprecursors include SiI(NR¹R²)₃ and each precursor molecule containsthree nitrogen donors, one iodide and no hydride functional group, havethe structural formula:

wherein R¹ and R² selected independently from C₃-C₆ alkyl, aryl, orhetero group and R¹ and R² may be joined to form a cyclicnitrogen-containing heterocycle.

Exemplary amino(iodo)silanes having the formula SiI(NR¹R²)₃ include:

The above listed SiI(NR¹R²)₃ precursors may be synthesized by firstloading the reaction flask with a hydrocarbon suspension of silicontetraiodide, chilling the solution to −78° C. and addition of ahydrocarbon solution containing six equivalents of the appropriateamine. The resulting suspension may be filtered over a glass frittedfilter and the solvent removed to afford the crude product.Alternatively, the above listed SiI(NR¹R²)₃ precursors may besynthesized by first reacting a chilled hydrocarbon solution containingthree equivalents of the appropriate amine with three equivalents of ahydrocarbon solution of an alkyl lithium reagent. The resulting lithiumamide suspension may then be added to a chilled hydrocarbon suspensioncontaining one equivalent of silicon tetraiodide followed by filtrationon a glass frit and removal of solvent to afford the product.

Herein, exemplary hydrocarbon solutions suitable for these synthesismethods include diethyl ether, pentane, hexane, or toluene. Theresulting suspension is filtered and the resulting solution distilled toremove solvent. Purification of the resulting liquid or solid is carriedout by distillation or sublimation, respectively. Except for the ligandcompounds Li[NR¹R²] and diaminosilane compounds all of the startingmaterials are commercially available. The ligand compound may besynthesized by combining a hydrocarbon solution of metalorganic salt(i.e., alkyl lithium) to a hydrocarbon solution of the appropriateamine. Diaminosilanes may be synthesized as taught by Dussarrat et al.in WO2013109401A1.

To ensure process reliability, the disclosed Si-containing film formingcompositions may be purified by continuous or fractional batchdistillation or sublimation prior to use to a purity ranging fromapproximately 95% w/w to approximately 100% w/w, preferably ranging fromapproximately 98% w/w to approximately 100% w/w. One of ordinary skillin the art will recognize that the purity may be determined by H NMR orgas or liquid chromatography with mass spectrometry. The Si-containingfilm forming compositions may contain any of the following impurities:ammonium salts; alkylamines, dialkylamines, alkylimines, THF, ether,pentane, cyclohexane, heptanes, toluene, halogenated metal compounds.Preferably, the total quantity of these impurities is below 0.1% w/w.The purified composition may be produced by recrystallization,sublimation, distillation, and/or passing the gas or liquid through asuitable adsorbent, such as a 4 Å molecular sieves.

The concentration of each solvent, such as THF, ether, pentane,cyclohexane, heptanes, and/or toluene, in the purified Si-containingfilm forming compositions may range from approximately 0% w/w toapproximately 5% w/w, preferably from approximately 0% w/w toapproximately 0.1% w/w. Solvents may be used in the Si-containing filmforming composition's synthesis. Separation of the solvents from thecomposition may be difficult if both have similar boiling points.Cooling the mixture may produce solid precursor in liquid solvent, whichmay be separated by filtration. Vacuum distillation may also be used,provided the composition is not heated above approximately itsdecomposition point.

The disclosed Si-containing film forming composition contains less than5% v/v, preferably less than 1% v/v, more preferably less than 0.1% v/v,and even more preferably less than 0.01% v/v of any of its analogs orother reaction products. This embodiment may provide better processrepeatability. This embodiment may be produced by distillation of theSi-containing film forming composition.

Alternatively, the disclosed Si-containing film forming compositions maycomprise between approximately 5% w/w to approximately 50% w/w of onecompound with the balance of the composition comprising a secondcompound, particularly when the mixture provides improved processparameters or isolation of the target compound is too difficult orexpensive. For example, the disclosed Si-containing film formingcompositions may be 40/60% w/w of SiHI₂(N(iPr)₂) and SiH₂I(N(iPr)₂). Themixture may produce a stable, liquid composition suitable for vapordeposition.

The concentration of trace metals and metalloids in the purifiedSi-containing film forming composition may each range independently fromapproximately 0 ppbw to approximately 100 ppbw, and more preferably fromapproximately 0 ppbw to approximately 10 ppbw. These metal or metalloidimpurities include, but are not limited to, Aluminum (Al), Arsenic (As),Barium (Ba), Beryllium (Be), Bismuth (Bi), Cadmium (Cd), Calcium (Ca),Chromium (Cr), Cobalt (Co), Copper (Cu), Gallium (Ga), Germanium (Ge),Hafnium (Hf), Zirconium (Zr), Indium (In), Iron (Fe), Lead (Pb), Lithium(Li), Magnesium (Mg), Manganese (Mn), Tungsten (W), Nickel (Ni),Potassium (K), Sodium (Na), Strontium (Sr), Thorium (Th), Tin (Sn),Titanium (Ti), Uranium (U), Vanadium (V) and Zinc (Zn). Theconcentration of X (where X═Cl, Br) in the purified Si-containing filmforming composition may range between approximately 0 ppmw andapproximately 100 ppmw and more preferably between approximately 0 ppmwto approximately 10 ppmw.

Care should be taken to prevent exposure of the disclosed Si-containingfilm forming compositions to water as this may result in decompositionof the amino(iodo)silane precursors.

The disclosed Si-containing film forming compositions may be deliveredto a semiconductor processing tool by the disclosed Si-containing filmforming composition delivery devices. FIGS. 1 and 2 show two embodimentsof the disclosed delivery devices 1.

FIG. 1 is a side view of one embodiment of the Si-containing filmforming composition delivery device 1. In FIG. 1, the disclosedSi-containing film forming composition 10 are contained within acontainer 20 having two conduits, an inlet conduit 30 and an outletconduit 40. One of ordinary skill in the precursor art will recognizethat the container 20, inlet conduit 30, and outlet conduit 40 aremanufactured to prevent the escape of the gaseous form of theSi-containing film forming composition 10, even at elevated temperatureand pressure.

Suitable valves include spring-loaded or tied diaphragm valves. Thevalve may further comprise a restrictive flow orifice (RFO). Thedelivery device should be connected to a gas manifold and in anenclosure. The gas manifold should permit the safe evacuation andpurging of the piping that may be exposed to air when the deliverydevice is replaced so that any residual amounts of the pyrophoricmaterial does not react. The enclosure should be equipped with sensorsand fire control capability to control the fire in the case of apyrophoric material release. The gas manifold should also be equippedwith isolation valves, vacuum generators, and permit the introduction ofa purge gas at a minimum.

The delivery device must be leak tight and be equipped with valves thatdo not permit escape of even minute amounts of the material. Thedelivery device fluidly connects to other components of thesemiconductor processing tool, such as the gas cabinet disclosed above,via valves 35 and 45. Preferably, the delivery device 20, inlet conduit30, valve 35, outlet conduit 40, and valve 45 are made of 316L EP or 304stainless steel. However, one of ordinary skill in the art willrecognize that other non-reactive materials may also be used in theteachings herein and that any corrosive Si-containing film formingcomposition 10 may require the use of more corrosion-resistantmaterials, such as Hastelloy or Inconel.

In FIG. 1, the end 31 of inlet conduit 30 is located above the surfaceof the Si-containing film forming composition 10, whereas the end 41 ofthe outlet conduit 40 is located below the surface of the Si-containingfilm forming composition 10. In this embodiment, the Si-containing filmforming composition 10 is preferably in liquid form. An inert gas,including but not limited to nitrogen, argon, helium, and mixturesthereof, may be introduced into the inlet conduit 30. The inert gaspressurizes the delivery device 20 so that the liquid Si-containing filmforming composition 10 is forced through the outlet conduit 40 and tocomponents in the semiconductor processing tool (not shown). Thesemiconductor processing tool may include a vaporizer which transformsthe liquid Si-containing film forming composition 10 into a vapor, withor without the use of a carrier gas such as helium, argon, nitrogen ormixtures thereof, in order to deliver the vapor to a chamber where awafer to be repaired is located and treatment occurs in the vapor phase.Alternatively, the liquid Si-containing film forming composition 10 maybe delivered directly to the wafer surface as a jet or aerosol.

FIG. 2 is a side view of a second embodiment of the Si-containing filmforming composition delivery device 1. In FIG. 2, the end 31 of inletconduit 30 is located below the surface of the Si-containing filmforming composition 10, whereas the end 41 of the outlet conduit 40 islocated above the surface of the Si-containing film forming composition10. FIG. 2, also includes an optional heating element 25, which mayincrease the temperature of the Si-containing film forming composition10. The Si-containing film forming composition 10 may be in solid orliquid form. An inert gas, including but not limited to nitrogen, argon,helium, and mixtures thereof, is introduced into the inlet conduit 30.The inert gas flows through the Si-containing film forming composition10 and carries a mixture of the inert gas and vaporized Si-containingfilm forming composition 10 to the outlet conduit 40 and on to thecomponents in the semiconductor processing tool.

Both FIGS. 1 and 2 include valves 35 and 45. One of ordinary skill inthe art will recognize that valves 35 and 45 may be placed in an open orclosed position to allow flow through conduits 30 and 40, respectively.Either delivery device 1 in FIG. 1 or 2, or a simpler delivery devicehaving a single conduit terminating above the surface of any solid orliquid present, may be used if the Si-containing film formingcomposition 10 is in vapor form or if sufficient vapor pressure ispresent above the solid/liquid phase. In this case, the Si-containingfilm forming composition 10 is delivered in vapor form through theconduit 30 or 40 simply by opening the valve 35 in FIG. 1 or 45 in FIG.2, respectively. The delivery device 1 may be maintained at a suitabletemperature to provide sufficient vapor pressure for the Si-containingfilm forming composition 10 to be delivered in vapor form, for exampleby the use of an optional heating element 25.

While FIGS. 1 and 2 disclose two embodiments of the Si-containing filmforming composition delivery device 1, one of ordinary skill in the artwill recognize that the inlet conduit 30 and outlet conduit 40 may bothbe located above or below the surface of the Si-containing film formingcomposition 10 without departing from the disclosure herein.Furthermore, inlet conduit 30 may be a filling port. Finally, one ofordinary skill in the art will recognize that the disclosedSi-containing film forming composition may be delivered to semiconductorprocessing tools using other delivery devices, such as the ampoulesdisclosed in WO 2006/059187 to Jurcik et al., without departing from theteachings herein.

Also disclosed are methods of using the disclosed Si-containing filmforming compositions for vapor deposition methods. The disclosed methodsprovide for the use of the Si-containing film forming compositions fordeposition of silicon-containing films. The disclosed methods may beuseful in the manufacture of semiconductor, photovoltaic, LCD-TFT, flatpanel type devices, refractory materials, or aeronautics.

The disclosed methods for forming a silicon-containing layer on asubstrate include: placing a substrate in a reactor, delivering into thereactor a vapor of the disclosed Si-containing film forming composition,and contacting the vapor with the substrate (and typically directing thevapor to the substrate) to form a silicon-containing layer on thesurface of the substrate.

The methods may include forming a bimetal-containing layer on asubstrate using the vapor deposition process and, more specifically, fordeposition of SiMO_(x) films wherein x is 4 and M is Ta, Hf, Nb, Mg, Al,Sr, Y, Ba, Ca, As, Sb, Bi, Sn, Pb, Co, lanthanides (such as Er), orcombinations thereof. The disclosed methods may be useful in themanufacture of semiconductor, photovoltaic, LCD-TFT, or flat panel typedevices. An oxygen source, such as O₃, O₂, H₂O, NO, H₂O₂, acetic acid,formalin, para-formaldehyde, oxygen radicals thereof, and combinationsthereof, but preferably O₃ or plasma treated O₂, may also be introducedinto the reactor.

The disclosed Si-containing film forming compositions may be used todeposit silicon-containing films using any deposition methods known tothose of skill in the art. Examples of suitable deposition methodsinclude chemical vapor deposition (CVD) or atomic layer deposition(ALD). Exemplary CVD methods include thermal CVD, pulsed CVD (PCVD), lowpressure CVD (LPCVD), sub-atmospheric CVD (SACVD) or atmosphericpressure CVD (APCVD), hot-wire CVD (HWCVD, also known as cat-CVD, inwhich a hot wire serves as an energy source for the deposition process),radicals incorporated CVD, plasma enhanced CVD (PECVD) including but notlimited to flowable PECVD, and combinations thereof. Exemplary ALDmethods include thermal ALD, plasma enhanced ALD (PEALD), spatialisolation ALD, hot-wire ALD (HWALD), radicals incorporated ALD, andcombinations thereof. Super critical fluid deposition may also be used.The deposition method is preferably ALD, PE-ALD, or spatial ALD in orderto provide suitable step coverage and film thickness control.

The vapor of the Si-containing film forming composition is generated andthen introduced into a reaction chamber containing a substrate. Thetemperature and the pressure in the reaction chamber and the temperatureof the substrate are held at conditions suitable for vapor deposition ofat least part of the amino(iodo)silane precursor onto the substrate. Inother words, after introduction of the vaporized composition into thereaction chamber, conditions within the reaction chamber are adjustedsuch that at least part of the precursor is deposited onto the substrateto form the Si-containing layer. One of ordinary skill in the art willrecognize that “at least part of the precursor is deposited” means thatsome or all of the precursor reacts with or adheres to the substrate.Herein, a reactant may also be used to help in formation of theSi-containing layer.

The reaction chamber may be any enclosure or chamber of a device inwhich deposition methods take place, such as, without limitation, aparallel-plate type reactor, a cold-wall type reactor, a hot-wall typereactor, a single-wafer reactor, a multi-wafer reactor, or other suchtypes of deposition systems. All of these exemplary reaction chambersare capable of serving as an ALD or CVD reaction chamber. The reactionchamber may be maintained at a pressure ranging from about 0.5 mTorr toabout 20 Torr for all ALD and subatmospheric CVD. Subatmospheric CVD andatmospheric CVD pressures may range up to 760 Torr (atmosphere). Inaddition, the temperature within the reaction chamber may range fromabout 20° C. to about 600° C. One of ordinary skill in the art willrecognize that the temperature may be optimized through mereexperimentation to achieve the desired result.

The temperature of the reactor may be controlled by either controllingthe temperature of the substrate holder or controlling the temperatureof the reactor wall. Devices used to heat the substrate are known in theart. The reactor wall is heated to a sufficient temperature to obtainthe desired film at a sufficient growth rate and with desired physicalstate and composition. A non-limiting exemplary temperature range towhich the reactor wall may be heated includes from approximately 20° C.to approximately 600° C. When a plasma deposition process is utilized,the deposition temperature may range from approximately 20° C. toapproximately 550° C. Alternatively, when a thermal process isperformed, the deposition temperature may range from approximately 300°C. to approximately 600° C.

Alternatively, the substrate may be heated to a sufficient temperatureto obtain the desired silicon-containing film at a sufficient growthrate and with desired physical state and composition. A non-limitingexemplary temperature range to which the substrate may be heatedincludes from 150° C. to 600° C. Preferably, the temperature of thesubstrate remains less than or equal to 500° C.

The reactor contains one or more substrates onto which the films will bedeposited. A substrate is generally defined as the material on which aprocess is conducted. The substrates may be any suitable substrate usedin semiconductor, photovoltaic, flat panel, or LCD-TFT devicemanufacturing. Examples of suitable substrates include wafers, such assilicon, silica, glass, or GaAs wafers. The wafer may have one or morelayers of differing materials deposited on it from a previousmanufacturing step. For example, the wafers may include silicon layers(crystalline, amorphous, porous, etc.), silicon oxide layers, siliconnitride layers, silicon oxy nitride layers, carbon doped silicon oxide(SiCOH) layers, or combinations thereof. Additionally, the wafers mayinclude copper layers or noble metal layers (e.g. platinum, palladium,rhodium, or gold). The layers may include oxides which are used asdielectric materials in MIM, DRAM, or FeRam technologies (e.g., ZrO₂based materials, HfO₂ based materials, TiO₂ based materials, rare earthoxide based materials, ternary oxide based materials such as strontiumruthenium oxide [SRO], etc.) or from nitride-based films (e.g., TaN)that are used as an oxygen barrier between copper and the low-k layer.The wafers may include barrier layers, such as manganese, manganeseoxide, etc. Plastic layers, such aspoly(3,4-ethylenedioxythiophene)poly(styrenesulfonate) [PEDOT:PSS] mayalso be used. The layers may be planar or patterned. For example, thelayer may be a patterned photoresist film made of hydrogenated carbon,for example CH_(x), wherein x is greater than zero.

The disclosed processes may deposit the silicon-containing layerdirectly on the wafer or directly on one or more than one (whenpatterned layers form the substrate) of the layers on top of the wafer.The substrate may be patterned to include vias or trenches having highaspect ratios. For example, a conformal Si-containing film, such asSiO₂, may be deposited using any ALD technique on a through silicon via(TSV) having an aspect ratio ranging from approximately 20:1 toapproximately 100:1. Furthermore, one of ordinary skill in the art willrecognize that the terms “film” or “layer” used herein refer to athickness of some material laid on or spread over a surface and that thesurface may be a trench or a line. Throughout the specification andclaims, the wafer and any associated layers thereon are referred to assubstrates. In many instances though, the preferred substrate utilizedmay be selected from hydrogenated carbon, TiN, SRO, Ru, and Si typesubstrates, such as polysilicon or crystalline silicon substrates. Forexample, a silicon nitride film may be deposited onto a Si layer. Insubsequent processing, alternating silicon oxide and silicon nitridelayers may be deposited on the silicon nitride layer forming a stack ofmultiple SiO₂/SiN layers used in 3D NAND gates.

The disclosed Si-containing film forming compositions may be suppliedeither in neat form or in a blend with a suitable solvent, such astoluene, ethyl benzene, xylene, mesitylene, decane, dodecane, octane,hexane, pentane, tertiary amines, acetone, tetrahydrofuran, ethanol,ethylmethylketone, 1,4-dioxane, or others. The disclosed compositionsmay be present in varying concentrations in the solvent. For example,the resulting concentration may range from approximately 0.05M toapproximately 2M.

The neat or blended Si-containing film forming compositions aredelivered into a reactor in vapor form by conventional means, such astubing and/or flow meters. The composition in vapor form may be producedby vaporizing the neat or blended composition through a conventionalvaporization step such as direct vaporization, distillation, bybubbling, or by using a sublimator such as the one disclosed in PCTPublication WO2009/087609 to Xu et al. The neat or blended compositionmay be fed in liquid state to a vaporizer where it is vaporized beforeit is introduced into the reactor. Alternatively, the neat or blendedcomposition may be vaporized by passing a carrier gas into a containercontaining the composition or by bubbling of the carrier gas into thecomposition. The carrier gas may include, but is not limited to, Ar, He,or N₂, and mixtures thereof. Bubbling with a carrier gas may also removeany dissolved oxygen present in the neat or blended composition. Thecarrier gas and composition are then introduced into the reactor as avapor.

If necessary, the container may be heated to a temperature that permitsthe Si-containing film forming composition to be in its liquid phase andto have a sufficient vapor pressure. The container may be maintained attemperatures in the range of, for example, 0-150° C. Those skilled inthe art recognize that the temperature of the container may be adjustedin a known manner to control the amount of Si-containing film formingcomposition vaporized.

In addition to the disclosed precursor, a reactant may also beintroduced into the reactor. The reactant may be an oxidizing agent,such as one of O₂, O₃, H₂O, H₂O₂; oxygen containing radicals, such as O.or OH., NO, NO₂; carboxylic acids such as formic acid, acetic acid,propionic acid, radical species of NO, NO₂, or the carboxylic acids;para-formaldehyde; and mixtures thereof. Preferably, the oxidizing agentis selected from the group consisting of O₂, O₃, H₂O, H₂O₂, oxygencontaining radicals thereof such as O. or OH., and mixtures thereof.Preferably, when an ALD process is performed, the reactant is plasmatreated oxygen, ozone, or combinations thereof. When an oxidizing agentis used, the resulting silicon containing film will also contain oxygen.

Alternatively, the reactant may be a reducing agent such as one of H₂,NH₃, (SiH₃)₃N, hydridosilanes (for example, SiH₄, Si₂H₆, Si₃H₈, Si₄H₁₀,Si₅H₁₀, Si₆H₁₂), chlorosilanes and chloropolysilanes (for example,SiHCl₃, SiH₂Cl₂, SIH₃Cl, Si₂Cl₆, Si₂HCl₅, Si₃Cl₈), alkylsilanes (forexample, (CH₃)₂SiH₂, (C₂H₅)₂SiH₂, (CH₃)SiH₃, (C₂H₅)SiH₃), hydrazines(for example, N₂H₄, MeHNNH₂, MeHNNHMe), organic amines (for example,N(CH₃)H₂, N(C₂H₅)H₂, N(CH₃)₂H, N(C₂H₅)₂H, N(CH₃)₃, N(C₂H₅)₃,(SiMe₃)₂NH), pyrazoline, pyridine, B-containing molecules (for example,B₂H₆, 9-borabicyclo[3,3,1]none, trimethylboron, triethylboron,borazine), alkyl metals (such as trimethylaluminum, triethylaluminum,dimethylzinc, diethylzinc), radical species thereof, and mixturesthereof. Preferably, the reducing agent is H₂, NH₃, SiH₄, Si₂H₆, Si₃H₈,SiH₂Me₂, SiH₂Et₂, N(SiH₃)₃, hydrogen radicals thereof, or mixturesthereof. Preferably, the reducing agent is SiHCl₃, Si₂Cl₆, Si₂HCl₅,Si₂H₂Cl₄, and cyclo-Si₆H₆Cl₆. When a reducing agent is used, theresulting silicon containing film may be pure Si.

The reactant may be treated by plasma, in order to decompose thereactant into its radical form. N₂ may also be utilized as a reducingagent when treated with plasma. For instance, the plasma may begenerated with a power ranging from about 50W to about 500W, preferablyfrom about 100W to about 200W. The plasma may be generated or presentwithin the reactor itself. Alternatively, the plasma may generally be ata location removed from the reactor, for instance, in a remotely locatedplasma system. One of skill in the art will recognize methods andapparatus suitable for such plasma treatment.

The disclosed Si-containing film forming composition may also be usedwith a halosilane or polyhalodisilane, such as hexachlorodisilane,pentachlorodisilane, or tetrachlorodisilane, and one or more reactantsto form Si, SiCN, or SiCOH films. PCT Publication Number WO2011/123792discloses a SiN layer, and the entire contents of which are incorporatedherein in their entireties.

When the desired silicon-containing film also contains another element,such as, for example and without limitation, Ta, Hf, Nb, Mg, Al, Sr, Y,Ba, Ca, As, Sb, Bi, Sn, Pb, Co, lanthanides (such as Er), orcombinations thereof, the reactants may include a another precursorwhich is selected from, but not limited to, alkyls, such as Ln(RCp)₃ orCo(RCp)₂, amines, such as Nb(Cp)(NtBu)(NMe₂)₃ or any combinationthereof.

The Si-containing film forming composition and one or more reactants maybe introduced into the reaction chamber simultaneously (e.g., CVD),sequentially (e.g., ALD), or in other combinations. For example, theSi-containing film forming composition may be introduced in one pulseand two additional reactants may be introduced together in a separatepulse (e.g., modified ALD). Alternatively, the reaction chamber mayalready contain the reactant prior to introduction of the Si-containingfilm forming composition. The reactant may be passed through a plasmasystem localized or remotely from the reaction chamber, and decomposedto radicals. Alternatively, the Si-containing film forming compositionmay be introduced to the reaction chamber continuously while otherreactants are introduced by pulse (e.g., pulsed-CVD). In each example, apulse may be followed by a purge or evacuation step to remove excessamounts of the component introduced. In each example, the pulse may lastfor a time period ranging from about 0.01 s to about 10 s, alternativelyfrom about 0.3 s to about 3 s, alternatively from about 0.5 s to about 2s. In another alternative, the Si-containing film forming compositionand one or more reactants may be simultaneously sprayed from a showerhead under which a susceptor holding several wafers is spun (e.g.,spatial ALD).

In one non-limiting exemplary ALD type process, the vapor phase of aSi-containing film forming composition is introduced into the reactionchamber, where at least part of the amino(iodo)silane precursor reactswith a suitable substrate, such as Si, SiO₂, Al₂O₃, etc., to form anadsorbed silane layer. Excess composition may then be removed from thereaction chamber by purging and/or evacuating the reaction chamber. Anoxygen source is introduced into the reaction chamber where it reactswith the absorbed silane layer in a self-limiting manner. Any excessoxygen source is removed from the reaction chamber by purging and/orevacuating the reaction chamber. If the desired film is a silicon oxidefilm, this two-step process may provide the desired film thickness ormay be repeated until a film having the necessary thickness has beenobtained.

Alternatively, if the desired film contains a second element (i.e.,SiMO_(x), wherein x may be 4 and M is Ta, Hf, Nb, Mg, Al, Sr, Y, Ba, Ca,As, Sb, Bi, Sn, Pb, Co, lanthanides (such as Er), or combinationsthereof), the two-step process above may be followed by introduction ofa vapor of a second precursor into the reaction chamber. The secondprecursor will be selected based on the nature of the oxide film beingdeposited. After introduction into the reaction chamber, the secondprecursor is contacted with the substrate. Any excess second precursoris removed from the reaction chamber by purging and/or evacuating thereaction chamber. Once again, an oxygen source may be introduced intothe reaction chamber to react with the second precursor. Excess oxygensource is removed from the reaction chamber by purging and/or evacuatingthe reaction chamber. If a desired film thickness has been achieved, theprocess may be terminated. However, if a thicker film is desired, theentire four-step process may be repeated. By alternating the provisionof the amino(iodo)silane precursor, second precursor, and oxygen source,a film of desired composition and thickness can be deposited.

Additionally, by varying the number of pulses, films having a desiredstoichiometric M:Si ratio may be obtained. For example, a SiMO₂ film maybe obtained by having one pulse of the Si-containing film formingcomposition and one pulses of the second precursor, with each pulsebeing followed by pulses of the oxygen source. However, one of ordinaryskill in the art will recognize that the number of pulses required toobtain the desired film may not be identical to the stoichiometric ratioof the resulting film.

In another alternative, dense SiCN films may be deposited using an ALDmethod with hexachlorodisilane (HCDS) or pentachlorodisilane (PCDS), thedisclosed Si-containing film forming composition, and an ammoniareactant. The reaction chamber may be controlled at 5 Torr, 550° C.,with a 55 sccm continuous flow of Ar. An approximately 10 second longpulse of the Si-containing film forming composition at a flow rate ofapproximately 1 sccm is introduced into the reaction chamber. Any excessSi-containing film forming composition is purged from the reactionchamber with an approximately 55 sccm flow of Ar for approximately 30seconds. An approximately 10 second pulse of HCDS at a flow rate ofapproximately 1 sccm is introduced into the reaction chamber. Any excessHCDS is purged from the reaction chamber with an approximately 55 sccmflow of Ar for approximately 30 seconds. An approximately 10 second longpulse of NH₃ at a flow rate of approximately 50 sccm is introduced intothe reaction chamber. Any excess NH₃ is purged from the reaction chamberwith an approximately 55 sccm flow of Ar for approximately 10 seconds.These 6 steps are repeated until the deposited layer achieves a suitablethickness. One of ordinary skill in the art will recognize that theintroductory pulses may be simultaneous when using a spatial ALD device.As described in PCT Pub No WO2011/123792, the order of the introductionof the precursors may be varied and the deposition may be performed withor without the NH₃ reactant in order to tune the amounts of carbon andnitrogen in the SiCN film.

In yet another alternative, a silicon-containing film may be depositedby the flowable PECVD method disclosed in U.S. Patent ApplicationPublication No. US2014/0051264 A1 using the disclosed compositions and aradical nitrogen- or oxygen-containing reactant. The radical nitrogen-or oxygen-containing reactant, such as NH₃ or H₂O respectively, isgenerated in a remote plasma system. The radical reactant and the vaporphase of the disclosed compositions are introduced into the reactionchamber where they react and deposit the initially flowable film on thesubstrate. Applicants believe that the nitrogen atoms of the aminogroups in the disclosed precursors help to further improve theflowability of the deposited film, resulting in films having less voidsor pores (i.e., dense films).

The silicon-containing films resulting from the processes discussedabove may include Si, SiO₂, SiN, SiC, SiON, SiCN, SiCON, SiCOH, orMSiO_(x), wherein M is an element such as Hf, Zr, Ti, Nb, Ta, or Ge, andx may be from 0-4, depending on the oxidation state of M. One ofordinary skill in the art will recognize that by judicial selection ofthe appropriate Si-containing film forming composition and reactants,the desired film composition may be obtained.

Upon obtaining a desired film thickness, the film may be subject tofurther processing, such as thermal annealing, furnace-annealing, rapidthermal annealing, UV or e-beam curing, and/or plasma gas exposure.Those skilled in the art recognize the systems and methods utilized toperform these additional processing steps. For example, thesilicon-containing film may be exposed to a temperature ranging fromapproximately 200° C. and approximately 1000° C. for a time ranging fromapproximately 0.1 second to approximately 7200 seconds under an inertatmosphere, a H-containing atmosphere, a N-containing atmosphere, anO-containing atmosphere, or combinations thereof. Most preferably, thetemperature is 600° C. for less than 3600 seconds under an H-containingatmosphere. The resulting film may contain fewer impurities andtherefore may have improved performance characteristics. The annealingstep may be performed in the same reaction chamber in which thedeposition process is performed. Alternatively, the substrate may beremoved from the reaction chamber, with the annealing/flash annealingprocess being performed in a separate apparatus. Any of the abovepost-treatment methods, but especially thermal annealing, has been foundeffective to reduce carbon and nitrogen contamination of thesilicon-containing film.

EXAMPLES

The following non-limiting examples are provided to further illustrateembodiments of the invention. However, the examples are not intended tobe all inclusive and are not intended to limit the scope of theinventions described herein.

Comparative Example 1 Synthesis and Properties of SiHI(NMe₂)₂

A flask containing tris(dimethylamino)silane (15.9 g, 0.099 mol) underan atmosphere of dry N₂ is chilled to 0° C. and triiodosilane (20.4 g,0.049 mol) is added at a rate of ˜1 mL/minute. Some fuming is observedinitially. The reaction is subsequently allowed to warm to roomtemperature and stirred for 16 hours to obtain a slightly cloudy, paleyellow liquid. The product is distilled over a short path column (30-35°C., 80-110 mTorr) to yield a colorless, air sensitive, free flowingliquid (23.3 g, 65% yield). The product identified asbis(dimethylamino)iodosilane was analyzed by GCMS which shows >95%purity. Structure and purity were confirmed by ¹H & ¹³C NMR.

The TGA analysis of SiHI(NMe₂)₂ is shown in FIG. 3. Both the open cupand closed cup TGA graphs show clean evaporation with a low (<1%)residue. The closed cup TGA shows a slight step at 100° C. due topresence of a small amount of starting material in the product. Oneskilled in the art will recognize that isolation of the product may bedifficult due to its similar boiling point to the starting reactant,SiH(NMe₂)₃.

Comparative Example 2 Synthesis of SiH₂I(NMe₂)

Under an atmosphere of dry N₂ at 23° C., tris(dimethylamino)silane (1.61g, 9.92 mmol) is added dropwise to a flask containing diodosilane (2.80g, 9.86 mmol). Some fuming is initially observed. After one hour ofstirring, a sample of the product mixture is dissolved indichloromethane (0.5 mL, 7.83 mmol) and analyzed by GCMS. Three productsare observed: dimethylamino(iodo)silane, dimethylamino(diiodo)silane andbis(dimethlyamino)iodosilane. The mixture is stored under dry N₂ for oneweek at 23° C. and analyzed again by GCMS where it is observed that thepeak area integration of dimethylamino(iodo)silane has significantlydecreased (from ca 12% to ca 2%) with the formation of decompositionproducts. This example confirms the results obtained by Anderson et al.showing that this product decomposes (J. Chem. Soc. Dalton Trans. 1987,pp. 3029-3034).

Comparative Example 3 Synthesis and Properties of SiH₂I(NEt₂)

Synthesis route: SiH₂(NEt₂)₂+SiH₂I₂→2SiH₂I(NEt₂) (neat reaction).

Under an atmosphere of pure N₂ a flask is charged with diiodosilane(SiH₂I₂) (41.2 g, 0.145 mol) and cooled to 0° C. Bis(diethylamino)silane(SiH₂(NEt₂)₂) (25.4 g, 0.146 mol) is chilled to 0° C. and then added ata rate of ˜0.5 mL/minute to the reaction flask. Fuming is observedduring the course of the addition. The reaction is subsequently allowedto warm to room temperature and stirred for 4 hours to obtain a cloudy,pale yellow liquid.

The crude product is then distilled over a short path column (30-32° C.,1.2 mTorr) to yield a colorless, air sensitive, free flowing liquid(57.3 g, 86% yield). The product was analyzed by GCMS & ¹H NMR whichshows >99% purity. The structure of the product is confirmed by ¹H, ¹³C& ²⁹Si NMR. Melting point is less than −70° C. Vapor pressure=10 Torr @27° C.

FIG. 4 is distilled SiH₂I(NEt₂) TGA data. As shown, the open cup TGAshows clean evaporation and low (<1%) residue for SiH₂I(NEt₂) bothbefore and after heating to 70° C. for 8 hours but thermally stressedmaterial shows a small step behavior (due to small % of decomposition).The closed cup measurement shows step behavior over ˜180° C. Thermalstability tests of SiH₂I(NEt₂) show solids formation upon heating overtime.

Comparative Example 4 Attempted Synthesis of SiH₂I(NHtBu)

Under an atmosphere of dry N₂ at 23° C., bis(tert-butylamino)silane(1.72 g, 9.86 mmol) is added dropwise to a flask containing diodosilane(2.80 g, 9.86 mmol). Some fuming and the formation of colorless solidsare observed. A sample of the product mixture is dissolved indichloromethane (0.5 mL, 7.83 mmol) and analyzed by GCMS. The observedproducts do not include the target compound (tert-butylamino)iodosilane.

Comparative Example 5 Attempted Synthesis of SiI₂(NMe₂)

Under an atmosphere of dry N₂, anhydrous toluene (30.0 mL, 0.284 mol)was added to a flask containing silicon tetraiodide (25.2 g, 0.047 mol)and equipped with a condenser. Tetrakis(dimethylamino)silane (10.4 g,0.051 mol) is added followed by triethylamine (1.0 mL, 0.007 mol) andthe mixture heated with stirring to form a yellow solution at 90° C. for6 hours. The reaction is cooled to 23° C. and an aliquot taken foranalysis by GCMS. The composition of the silicon containing products isobserved as follows: Si(NMe₂)₄ (60.1%), SiI(NMe₂)₃, (2.2%), SiI₂(NMe₂)₂(3.1%), SiI₃(NMe₂) (3.7%) and SiI₄(NMe₂) (30.9%).

Example 1 Synthesis and Properties of SiH₂I(N(iPr)₂)

Synthesis Route: SiH₂I₂+SiH₂(N(iPr)₂)₂→2SiH₂I(N(iPr)₂) (neat reaction)

Under an atmosphere of pure N₂ a flask is charged with diiodosilane(28.5 g, 0.100 mol). At 24° C., bis(diisopropylamino)silane (23.4 g,0.101 mol) is added at a rate of ˜1 mL/minute and stirred for 4 hours toobtain a cloudy, pale yellow liquid.

The crude product is then distilled over a short path column (25-30° C.,80-120 mTorr) to yield a colorless, air sensitive, free flowing liquid(43.2 g, 84% yield). The product was analyzed by GCMS & ¹H NMR whichshows >99% purity. Structure confirmed by ¹H, ¹³C & ²⁹Si NMR. ¹H & ²⁹SiNMR confirms GCMS, shows single product SiH₂I(N(iPr)₂). ¹³C NMR showsexpected peaks for clean product SiH₂I(N(iPr)₂). Melting point is −8° C.Vapor pressure @ 41° C. is 10 Torr. Density @ 24° C. is 1.35 g/mL.Viscosity @ 24° C. is 1.42 cSt

FIG. 5 shows distilled SiH₂I(N(iPr)₂) TGA data. As shown, the open cupTGA shows clean evaporation and low (<1%) residue for SiH₂I(N(iPr)₂)both before and after heating to 80° C. for 8 hours: shows goodstability. The closed cup measurement shows step behavior over 200° C.Thermal Test @ 80° C. for 8 hrs demonstrates <1% decomposition showingsolids formation upon heating over time.

Example 2 Synthesis and Properties of SiH₂I(N(iBu)₂)

Synthesis Route is SiH₂I₂+SiH₂(N(iBu)₂)₂→2SiH₂I(N(iBu)₂) (neat reaction)

Under an atmosphere of pure N₂ a flask is charged with diiodosilane(15.6 g, 0.055 mol) and cooled to 0° C. Bis(dibutylamino)silane (15.8 g,0.055 mol) is chilled to 0° C. and then added at a rate of ˜1 mL/minuteto the reaction flask. Fuming is observed initially. The reaction issubsequently allowed to warm to room temperature and stirred for 6 hoursto obtain a cloudy, pale yellow liquid.

The crude product is then distilled over a short path column (33-37° C.,50-70 mTorr) to yield a colorless, air sensitive, free flowing liquid(27.6 g, 88% yield). The product was analyzed by GCMS which shows >99%purity. Structure confirmed by ¹H, ¹³C & ²⁹Si NMR.

FIG. 6 shows distilled SiH₂I(N(iBu)₂) TGA data. As shown, the open cupTGA shows clean evaporation and low (<1%) residue for SiH₂I(N(iBu)₂)both before and after 8 hour thermal test @ 70° C. The closed cup TGAshows slightly higher residue (approximately 4%).

The properties of SiH₂I(N(iBu)₂) are as follows.

Distilled SiH₂I(N(iBu)₂) Vapor Pressure=1 Torr @ 29° C.

MP=<−70° C.

¹H & ²⁹Si NMR confirms GCMS shows single product SiH₂I(N(iBu)₂).

¹³C NMR confirms GCMS shows single product SiH₂I(N(iBu)₂).

Purity (GCMS & ¹H NMR) >99%.

Density=1.28 g/mL @ 24° C.

Viscosity=1.79 cSt @ 24° C.

Example 3 Stability

FIG. 7 is a graph showing purity over time for the precursors includedin Examples 1 and 2 and Comparative Example 3 stored at 24° C. FIG. 8 isa graph showing purity over time for the precursors included in Examples1 and 2 and Comparative Example 3 stored at 40° C. (SiH₂I(NEt₂)) and 50°C. (SiH₂I(N^(i)Pr₂) and SiH₂I(N^(i)Bu₂)). The purity was determined byGas Chromatography/Mass Spectrometry.

As shown in FIG. 7, after 12 weeks at room temperature, the purities ofSiH₂I(N(iBu)₂) and SiH₂I(N(iPr)₂) decrease approximately 1% and 4%respectively, while the purity of SiH₂I(NEt₂) decreases 19%. FIG. 8demonstrates that the purity of SiH₂I(NEt₂) decreases even more at 40°C., 44% at 12 weeks. In contrast, (SiH₂I(N^(i)Pr₂) decreases 2% after 4weeks and 4% after 12 weeks at 50° C. SiH₂I(N^(i)Bu₂)) decreases only 1%after 4 weeks at 50° C. Insufficient material was available to providefurther data points for SiH₂I(N^(i)Bu₂)). FIGS. 7 and 8 demonstrate thatSiH₂I(N(iBu)₂) has better thermal stability over time at a broadtemperature range, for example, ranging from room temperature to 50° C.

Example 4 Deposition Using SiH₂I(N^(i)Bu₂)

PEALD test were performed using SiH₂I(N^(i)Bu₂) which was placed in abubbler at room temperature (approx. 23° C.). Typical PEALD conditionswere used, such as using nitrogen direct plasma with excitationfrequency at 13.56 Mhz, and reactor pressure fixed at 1 Torr. Wafertemperature was measured at 250° C. and deposition was performed on puresilicon wafers.

FIG. 9 is a graph showing the deposition rate and refractive index as afunction of the precursor introduction pulse time in seconds. Asillustrated in FIG. 9, initial R&D testing did not produce the typicalALD saturation plateau that results from substrate saturation. The filmproperties below were obtained from a 5 second precursor pulse, 10second N₂ purge, 7 second N₂ plasma pulse at 200 W, and 3 second N₂purge.

The refractive index values are characteristics of SiN film (1.9-2.0).The film wet etch rate (WER) was obtained using 0.1% HF dilutedsolution. The WER of was measured at 96 Å/min.

XPS analysis of the resulting 193 Å thick film shows a Si-rich filmhaving very low iodine contamination as follows: Si of 48.9 atomic % (at%), N of 38.3 at %, O of 3.2 at %, C of 9.4 at %, and I of 0.2 at %.This analysis was performed on the uncapped film at a R&D facility,therefore the oxygen concentration may be due to post deposition airexposure. One of ordinary skill in the art will recognize that theseinitial R&D results are promising and that optimization of the PEALDprocess may further improve these results.

Example 5 Deposition Using SiH₂I(N^(i)Pr₂)

PEALD test were performed using SiH₂I(N^(i)Pr₂) which was placed in abubbler at room temperature (approx. 23° C.). Typical PEALD conditionswere used, such as using nitrogen direct plasma with excitationfrequency at 13.56 Mhz, and reactor pressure fixed at 1 Torr. Wafertemperature was measured at 250° C. and deposition was performed on puresilicon wafers.

FIG. 10 is a graph showing the deposition rate and refractive index as afunction of the precursor introduction pulse time in seconds. Asillustrated in FIG. 10, initial R&D testing did not produce the typicalALD saturation plateau that results from substrate saturation, buttesting remains ongoing. However, as the analysis below reveals, theresulting silicon nitride films have properties that may be suitable forcommercial applications. More particularly, the 0.8 Å/cycle depositionrate and 1 Å/minute wet etch rate may be suitable for applications thatrequire quick deposition of sacrificial silicon nitride films. The filmproperties below were obtained from a 7.5 second precursor pulse, 5second N₂ purge, 7 second N₂ plasma pulse at 200 W, and 3 second N₂purge. The refractive index values are on the low end of typical SiNfilm values (1.9-2.0). The film wet etch rate (WER) was obtained using0.1% HF diluted solution. The WER was measured at 102 Å/min.

XPS analysis of the resulting 542 Å thick film shows a Si-rich film asfollows: Si of 48.8 at %, N of 42.2 at %, 0 of 1.2 at %, C of 7.7 at %,and I of 0.1 at %. This analysis was performed on the uncapped film at aR&D facility, therefore the oxygen concentration may be due to postdeposition air exposure.

Comparative Example 6 Deposition Using SiH₂Cl(N^(i)Pr₂)

PEALD test were performed using SiH₂Cl(N^(i)Pr₂) which was placed in abubbler at room temperature (approx. 23° C.). Typical PEALD conditionswere used, such as using nitrogen direct plasma with excitationfrequency at 13.56 Mhz, and reactor pressure fixed at 1 Torr. Wafertemperature was measured at 250° C. and deposition was performed on puresilicon wafers.

FIG. 11 is a graph showing the deposition rate and refractive index as afunction of the precursor introduction pulse time in seconds. Asillustrated in FIG. 11, initial R&D testing did not produce the typicalALD saturation plateau that results from substrate saturation, buttesting remains ongoing. Additionally, the deposition rate was veryslow, making the process unsuitable for commercial applications. Thefilm properties below were obtained from a 10 second precursor pulse, 10second N₂ purge, 7 second N₂ plasma pulse at 50 W, 3 second N₂ purge.The refractive index values are characteristics of SiN film (1.9-2.0).The film wet etch rate was obtained using 0.1% HF diluted solution. TheWER was measured at 6 Å/min.

XPS analysis of the resulting 66 Å thick film shows Si-rich film and nochlorine contamination as follows: Si of 43.5 at. %, N of 47.0 at. %, 0of 6.8 at. %, C of 2.7 at. %, and Cl of 0.0 at. %.

It will be understood that many additional changes in the details,materials, steps, and arrangement of parts, which have been hereindescribed and illustrated in order to explain the nature of theinvention, may be made by those skilled in the art within the principleand scope of the invention as expressed in the appended claims. Thus,the present invention is not intended to be limited to the specificembodiments in the examples given above and/or the attached drawings.

What is claimed is:
 1. A method of depositing a sacrificial Siliconnitride layer on a substrate, the method comprising: introducing a vaporof SiH₂I(N(iPr)₂) and/or SiH₂I(N(iBu)₂) into a reactor having asubstrate disposed therein and depositing at least part ofSiH₂I(N(iPr)₂) and/or SiH₂I(N(iBu)₂) onto the substrate; introducing anitrogen-containing reactant into the reactor to form the sacrificialsilicon nitride layer at a rate ranging from approximately 0.5 Å/cycleto approximately 1 Å/cycle using a vapor deposition method; and removingthe sacrificial silicon nitride layer at a rate of approximately 102Å/minute.
 2. The method of claim 1, wherein the vapor deposition methodis PEALD.
 3. The method of claim 1, wherein the nitrogen-containingreactant is N₂.
 4. A method of depositing a sacrificial Silicon nitridelayer on a substrate, the method comprising: introducing a vapor ofSiH₂I(N(iPr)₂) and/or SiH₂I(N(iBu)₂) into a reactor having a substratedisposed therein; depositing at least part of SiH₂I(N(iPr)₂) and/orSiH₂I(N(iBu)₂) onto the substrate to form the sacrificial siliconnitride layer using a vapor deposition method; and removing thesacrificial silicon nitride layer at a rate of approximately102Å/minute.
 5. The method of claim 4, further comprising introducing anitrogen-containing reactant into the reactor to react with theSiH₂I(N(iPr)₂) and/or SiH₂I(N(iBu)₂) and form the sacrificial siliconnitride layer.
 6. The method of claim 5, wherein the nitrogen-containingreactant is N₂.
 7. The method of claim 5, wherein the vapor depositionmethod is PEALD.